Two different groups disagreed and fought, eventually involving a crowd of 300 to 400 people. The groups confronted each other again two days later. The second time, police were able to quickly resolve the situation.

Photos and videos of the Foxconn fight were passed around Chinese social media on Monday, though they couldn’t be independently verified.

Images of the incident showed about 40 shirtless men with pipes and sticks on the company’s campus. Police were seen in the video trying to restrain the men.

Newser notes that, while Foxconn said 11 people were injured, unconfirmed reports say the number was higher. One claimed that three people died in the fight, while another suggested that 27 people were hurt badly enough to require hospitalization.

The violence at Foxconn last week shows a similar, though much smaller, pattern. Another fight last year at a different campus began with two drunken workers and eventually spread to involve more than 2,000. The rapid escalation of fighting at Foxconn facilities points to a larger issue for the company.

Labor activists believe the quick escalation of fighting at the plants shows the pressure workers are under. Employees often travel from far away and work long hours. The company has defended its treatment of workers, even though an outside audit found widespread breaches of work rules.

Foxconn isn’t the only Chinese factory to see fights and other unrest. Data from China Labor Bulletin shows that there were 183 strikes and protests at the facilities from June through August.